USB: double put_tty_driver(gs_tty_driver) in gserial_setup()

If the driver cannot be registered, put_tty_driver(gs_tty_driver)
occurred here as well as at label fail.

put_tty_driver() already occurs at label fail
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/u_serial.c

@@ -1114,7 +1114,6 @@ int __init gserial_setup(struct usb_gadget *g, unsigned count)
 	/* export the driver ... */
 	status = tty_register_driver(gs_tty_driver);
 	if (status) {
-		put_tty_driver(gs_tty_driver);
 		pr_err("%s: cannot register, err %d\n",
 				__func__, status);
 		goto fail;